Device for dressing screw-threadgrinding disks



P 3, 1940- H. BRENDEL El" AL 2,213,665

DEVICE FOR DRESSING SCREW-THREAD-GRINDING DISKS Filed April 2', 195aPatented Sept. 3, 1940 DEVICE FOR GRIND I Hans Brendel and ErichBuchhols, Hamburg- Wandsbek, Germany,

Schaurte, Nenss-on-the-Rhine, corporation of Germany 2, 1 938, Serial NApril 3, 1937 Application April In Germany 4 Claims.

This invention relates to a device for dressing disks for grindingscrew-threads.

Heretoforain the grinding of screw-threads,

it has been practically impossible to obtain microscopic trueness in thegrinding disk. This was fundamentally true because in trimming thegrinding disk withgrinding tools, primarily diamond cutters, thetrimming was done by putting the cutters against the grinding disk andcutting w one side first, and then cutting the opposing side. In thismanner, the grinding disk resulting was untrue and consequently unfitfor precision work.

Other means have been suggested, but none have been successful, sincethe pressures of the grinding and profile-finishing tools were unequalon opposing sides of the grinding disk per se.

The present invention contemplates utilizing an apparatus wherein thediamond-trimming -finishing tools afford equal and pposite pressures onthe respective grinding surfaces of the disk to be dressed.

It is an object of this invention to provide grinding disk trimmingmeans wherein the pres- 35 sures of the disk trimmers per se will beequal and opposite againstthe grinding disk.

A further object dressing grinding disks per se by causing a series oftools to engage opposite sides of the grinding surfaces of agrindingdisk while utilizing equal tool pressures simultaneously onopposite sides of the working flanks of a grinding disk.

Further and other objectsmay become apparent to those skilled in the artfrom a perusal 8 of the drawing and specification herewith.

Inthe drawing: Fig. 1 shows diagrammatically a dressing device for ascrew-thread-grinding disk;

Fig. 2 shows subst 40 in Fig. 1, but the arrangement thereof isdifferent to present special working conditions; and

- trimming of the whe is to provide a device for upon the pressuresantialiy the same parts as and other round thread Fig. 3 shows insection a device for effecting the external roundings of the grindingdisk for 45 the production of round thread profiles.

similar characters of reference indicate cor-. responding partsthroughout the various views.

Referring more, particularly to Fig. l, the dressing oi the flanks of aprofile grinding disk 50 by means of simultaneous longitudinally movingtools is carried out. The diamond carriers d provided with the diamondsd' are adapted to be greciprocated in their holders in' the direction ofthe arrows H; In the embodiment illustrated, the flanks a v work.

nnessmo scnEw-rnnmnmo msxs .assigno'rs to Bauer & Germany, a

and b of the disks are shouldered, providing the transition stages o. Itwill be seen from Fig. 2 that the disk I0 is engaged on one side bydiamonds d carried by the tool carrier H. The diamonds d' of the toolcarrier II are moved 5 out of engagement with the disk it. The resultantpressure therefore causes the displacement angle it between the truecenter shown as dashdot line ii,-,and the resultant center shown bydash-dot line It caused by the pressure of the tools of the tool carrieris. 1' Q It. will therefore be seen that tol produce the el It by theputters d of essure of necessity must be ible to avoid the disk from Mto substantially a line tool carrier M, the pr such thatit is impossmoving from the line approximating line It.

In Fig. 1 it is seen thatthe tool carriers d have the individualcomponents l2 and i3, which com-' ponents may move to and fro along theflanks a and b of the grinding disk, and said to and fro movement may beeither in the same general direction at one time, or they'may be movingin opposite directions at substantially the same time. Whether or notthe tool carriers 12 and as move in the same general direction, orwhether one moves in one direction while the other moves in an oppositedirection, is entirely dependent presented by the diamonds to thesurfaces. at and b of the grinding disk. The displacement caused by themovement of the tool carriers i2 and I3 in the directions ofthe ar= rowsii is generally quite small as long as the diamond cutters on oppositesides of the disk are engaging the disk simultaneously, there will besubstantially an absolute elimination of the angle h. 1

Fig. 3 shows how the end faces care used for the production or dressingof the concave, rounding or curved working face e on Whltworth profiles.There is also shown the mode of operation of a disc or roller f ofsteel, hard metal or the like, which produces the convex roundingsurfaces e simultaneously with the rounding of the core-forming portionor apex g on the grinding disk. The parts c and 0', shown dotted,indicate the contour of the wheel l0 after trimming. with the diamondand before engagement with the roller or tool 1 which is in fact aprofile-finishing tool which eliminates the necessity of forming theprofile with diamond cutters. This is quite essential on grinding diskswhere the profile is extremely minute and is used for microscopicprecision A The roller or tool I moves at right angles to the axis ofthe grinding disk, so that'the pres sures on the surfaces 0, whichsurfaces are disposed on opposite sides of the grinding disk, willreceive equal pressure when the tool 1 is urged against the grindingdisk In in properalignment.

It will therefore be seen that in both the diamond trimming andproflle-flnishingoperation's of the complete dressing of the grindingwheel, the pressures on opposing flanks of the grinding surfaces aresubstantially equal and opposite throughout all dressing operations.

What we claim as new,'and desire to secure by Letters Patent of theUnitedStates is:

v the point in a higher plane than the other dial. A device for dressingscrew-threaded grinding disks, comprising two rigid carriers, eachsupporting two diamonds, the carriers being disposed so that thediamonds move in planes each parallel to the flank surfaces of the diskto be dressed, said diamonds being disposed in difierent planes, thediamonds for the flanks forming the point being in ahigher plane thanthe other diamonds in that the pointflanks are set inwardly in respectto the other flanks, means for moving said two carriers against bothflanks at the same time, and means limiting the active movement of onediamond of each carrier by the'other.

grinding disks, comprising two rigid carriers, each supporting twodiamonds, the carriers being disposed so thatthe diamonds move in planeseach parallel tothe flank surfaces of the disc to be dressed, saiddiamonds being disposed in different planes, the diamonds for the flanksforming to each other, and a proflle roller for simultane- I ouslyfurther dressing the disk at its point for convexly rounding the same,and at its shoulders for concavely rounding the same.

3. In a device for dressing screw-threaded t grinding disks, comprisingtwo rigid carriers, each supporting two diamonds, the'carriers beingdisposed so that the diamonds may move in planes parallel to theproposed flank surfaces of the 7 disk to be trimmedfsaid diamonds beingdisposed in different planes, the diamonds for the flanks forming thepoint in a higher plane than'the other diamonds in that the point flanksare set V 4. In a device for dressing screw-threaded.

grinding disks, comprising two rigid carriers, each supporting twodiamonds, the carriers being disposed so that the diamonds may move inplanes parallel to the proposed flank surfaces of the disk to betrimmed, said diamonds being disposed in different planes, the diamondsfor the flanks forming the point in a higher plane than the otherdiamonds in that the point flanks are set inwardly in respect to theother flanks, and means limiting the active movement of one diamond ofeach carrier by the other diamond of the same carrier, said meansincluding a shoulder formed between the flanks, means to permit said twocarriers to impinge opposing flanks of the grinding disk simultaneouslywhile both c'arriers are moving in the same general direction, andcore-forming, profile-finishing means moving at from the axis of thegrinding disk to engage said disk shoulders formed between the flanks oneach side of said'disk to make said flanks concave incontour. 1

HANS BRENDEL. an on BUCHHOLZ.

